Aimlessly wandering from a retirement home on the day of his first triple-digit birthday, Allan Karlsson unwittingly acquires a fortune in drug money. A caravan of unsavory biker thugs (apparently trained at the Home Alone school for comic criminals) gives chase. Oblivious to his pursuers (indeed, to his surroundings), Karlsson attracts a quirky retinue, people to whom he can tell the story of his life. In flashbacks, his love of explosives propels him through a series of global conflicts. The man caroms from Franco to Oppenheimer, from Truman to Stalin, in a string of improbable near misses that might remind seasoned cinephiles of Mark Sandrich’s collaborations with Astaire and Rogers — most notably 1935’s Top Hat.

Comparisons to Forrest Gump are inevitable. But Karlsson is a more passive character. An apter doppelgänger might be Chance the gardener, played to incognizant perfection by Peter Sellers in Being There (1979). He shrugs through life hardly exerting even the effort required to hold an opinion, much less an allegiance. An interview with director Felix Herngren suggests this lifelong ennui is the consequence of a eugenicist’s scalpel. But filmmakers are often stranded in the gulf between intending and demonstrating a character’s interior motive.

The enjoyable Hundraåringen deserves special mention for its clever redressing of locations, certainly its make-up, and definitely its pyrotechnics.